Sealing system for container closures



Oct 20, 1942 F. w. SAMPLE SEALING SYSTEMS FOR CONTAINER CLOS'URES FiledNov. 6, 1957 INVENTOR,

'FLEEK .W. SAMPLE Mz @532W ATTORNEY. v

Patented Oct. 20, 1942 SEALING SYSTEM FORCQNTAIN'E'R CLOSURES Fleck W.Sample, Forest Hills, N. Y., assigner to American Flange & ManufacturingCo., Inc., New York, N. Y., a corporation of Illinois ApplicationNovember 6, 1937, Serial No. 173,123

7 Claims.

This invention relates to sealing means for container closures andparticularly to sealing caps to be used in conjunction with hollowheaded plugs.

An object of this invention is to provide sealing means for the closureparts of a container when said closure parts have been attached to saidcontainer without provision having been made for -the reception ofsealing means.

Another object of the invention is to provide sealing means forclosures, which closures have been converted from one type toA another,wherein the origin-a1 type made lno provision for the receptionofsealing means.

Another obj-ect of the invention is to provide sealing means to preventundetectable tampering with closure plugs lfor containers without anymodification of the closure plug being necessary.

Stillanother object of the invention is to provide sealing means to bereceived within hollow headed plugs toY prevent removal of such plugswithout destruction of the sealing means.

A- further object of the invention resides in the provisionof means onsealing caps received in the heads of hollow plugs to prevent removalof-such caps from the plugs without the same being rst mutilated.

A further object of the invention resides in the method of providingsealing means for container closures after the same have beenconstructed without any provision of means to seal them.

-Other objects of the invention will in part be obvious and will in partappear in connection with the description taken in conjunction with theaccompanying drawing.

Closures for metal drums or the like in Atheir earlier forms were notparticularly leak-proof and were rather cumbersome and bulky inconstruction. An example of this is the type where the iiangeor bushingwas a heavy pieceof metal welded to the drum stock by spot-welding andthe screw plug was formed of cast iron with threads moreor less roughlyformed and with a head having a laterally extending flange. Between-that ange and the outer surface of the bushing member a at ring typegasket was received which was intended to prevent leakage or seepage ofthe contents of the container. Quite -commonly such closure fittings didnot prevent such leakage or seepage and since the investment inreturnable drums to which Vsuch come necessary to devise means forpreventing leakage from such drums.

The instant rinvention not only provides a method Afor converting thepreviously unsatisfactory closures into closures whose satisfactoryfunctioning is attested to-by their universal adoption, but alsoprovides sealing means which well guard the -converted closures againsttampering in spitleof the fact that no provision for sealing was'made intheforiginal fittings. The conversion has been accomplished byaccurately countersinking a gasket receiving surface around the mouth ofthe flange or bushing opening so that when screw plugs of the types setforth in United-States Patents-Nos. 2,040,088, 1,901,196 and 1,982,145,are inserted in the bushing their gaskets will engage the countersunkgasket receiving surface of the bushing and provide a leak-proofclosure.

To complete the conversion and prevent unauthorized tampering with thecontents of the containers, a seal cap designed to be received withinthe hollow head of a plug has been devised. This seal cap takes somewhatthe form of an inverted `dish having a top which closes the opening yinthe hollow plug and a skirt portionv designed to engage the peripheralwall of the 4hollow plug, and projections therefrom, in such a manner asto prevent removal of the cap without destroying the same. As the captop bridges and closes the hollow head of the plug the same cannot beremoved while the cap is intact. Furthermore, as the cap itself cannotbe removed and replaced while intact, it can be readily seen thatunauthorized tampering Ywithfthe closure will be clearly indicated.

For a fuller understanding of the nature and objects of th'e inventionreference should `be had to the following detailed description of theimprovements taken in conjunction with the'a'ccompanyingA drawing inwhich:

Figure 1 is a plan view ofv a closure according to the invention showingpart of the bushing member with a plug received therein, which plugissealed by a cap.

Fig. 2 is a sectional elevation on lines 2 2 of Fig. l.

Fig. 3 is a perspective view of the seal cap shown in Fig. 1.

Fig. 4 is a partial plan view of a closure including a different form ofscrew plug in which isreceived-another form of seal cap.

Fig. 5. is a partial sectional elevation oi the fittings wereapplied is-considerablait has beclosureof Fig. 4.

And Fig. 6 is a perspective view of the form of seal cap shown in F'ig.4.

In Figs. 1 and 2 there is shown at 5 a portion of a bushing or flangeemployed as one of the elements of the closure for a drum, container, orthe like. This bushing or flange is provided with an opening 6 which isscrew threaded for part of its length as shown at 1. The mouth ofopening 6 is Countersunk by means of a tool, particularly adapted forthe purpose, to provide a gasket engaging surface 8. As surface 8 isnotV formed during the formation of the flange and its opening, caremust be taken in its later formation to have it concentrically locatedwith respect to the opening and at the proper angle with respect to theaxis of the opening, for reasons that will appear hereinafter.

Received in opening 6 and threaded into positions therein as shown inFigs. 1 and 2 is a screw plug 9 of the type shown in United StatesPatent No. 1,901,196. Plug 9 is provided with a head I of slightlylarger diameter than the diameter of its threaded body portion whichbody portion is provided immediately beneath head I0 with a gasketreceiving surface |2 which carries a gasket I3, all as set forth inPatent No. 1,982,145. As is apparent from the showing in Fig. 2, theplug 9 can be screwed down until its head ID enters the mouth formed bygasket receiving seat 8. The extent of this travel of the plug head intothe Countersunk seat is predetermined to allow sufficient compression ofgasket I3, and is limited by the lower edge I4 of the head engaging thesurface 8 to prevent gasket I3 from being subjected to sufficientpressure to destroy it. The inward travel of plug head I9 with respectto the tapered surface 8 is also so chosen that when the plug 9 isscrewed home to its proper position, head I9 thereof will project butslightly above the upper surface of bushing or flange 5. The purpose ofthis latter is to eliminate the chances of the plug when seated inposition being contacted and damaged by extraneous objects.

The hollow head I5 of plug 9 has a at bottom surface I6, side wall I'Iand inwardly extending lugs I8. Received within said hollow head |5 is aseal cap as shown per se in Fig. 3. This seal cap has a disc-like top I9and a laterally extending skirt-like portion 29. At diametricallyopposed points of disc I9 and continuing down throughout the depth ofskirt 29 are formed similar channelled depressions 2| Whose formation issuch as to snugly embrace lugs I8 of plug 9. Skirt 29 is dimensioned tosnugly embrace the side wall of plug 9 and is of a depth to support discI9 flush with the top surfaces of lugs I8.

In order to prevent undetected removal of the seal cap, the dimensionsof skirt and the side walls 22 and bottom wall 23 of depressions 2| areso chosen that it is necessary to tap the seal cap with a mallet inorder to insert it. As is obvious from the relation of skirt 20 anddepressions 2I, the action of driving the seal cap into position willset up opposing forces acting to create a binding of the seal cap withrespect to the side wall and lugs I8 of plug 9. Since this binding forceacts horizontally with respect to the plug and lug walls, and as thehead I9 of the seal cap is ush with the top of plug head 9, it isreadily apparent that it would be exrather than being directlythereover.

When a drum equipped with closure plugs sealed in this manner reachesits destination, the seal cap can readily be pierced at 25, torn alongscore lines 24 and removed, whence a wrench can be applied to the plugfor removing the same.

In Figs. 4, 5 and 6 there is shown the manner in which a screw plug ofthe type set forth in United States Patent No. 2,040,088 can be sealed.In this form the engagement of the plug with the fiange or bushing isidentical to that shown in Figs. 1-3; the flange or bushing being shownat 35 with an opening at 35 having screw threads 31. Countersunk gasketreceiving surface 39 is provided at the mouth of opening 36 and screwplug 39 is shown as provided with a head 40, a threaded body portion 4|and a gasket receiving surface 42 carrying a gasket 43. Here also thelower peripheral edge of the plug head 44 engages the tapered surface 38in a manner to act as a stop and prevent the destruction of gasket 43.

The hollow head 45 of the plug in this instance differs slightly fromthat of Figs. 1-3, inasmuch as the means to facilitate removal of theplug is a bar 48 extending diametrically acrossrthe interior thereof andextending upwardly from bottom surface 46, a distance slightly less thanthe height of side wall 4'| of the plug.

In Fig. 6 there is shown the type of seal cap employed with theY plug ofFigs. 4 and 5. This consists of a top in the form of a complete disc 49and a laterally extending skirt 50 which has a return bent lip 5I at itsbottom, the upper end of which lip has an outer engaging surface 52.

VPortions of skirt 59 are removed at opposed sides thereof as shown at53, providing an opening of such dimension that its sides 54 closelyembrace the sides of cross piece 48. Skirt 59 is slightly outwardlybulged intermediate of its extent, as shown at 55, in order to enhancethe resiliency thereof.

The seal cap of Fig. 6 is inserted into the hollow head of plug 29 bytapping with a mallet similarly to the seal cap of Fig. 3. In thisinstance, the disc-like top 43 completely covers the hollow in the headof the plug -as well as covering bar 49. Here again, however,unauthorized removal of the seal cap is prevented by the fact that thetop surface of disc 49 lies very slightly below the top surface 49 ofthe plug head, thereby preventing insertion of a removing toolthereunder. This position of top 49 is due to proper dimensioning ofskirt 50 and to the fact that bar 48 has its top surface spaced slightlymore than the thickness of disc 49 below the top surface 49of plug 39.As is obvious from the drawing the retaining edge 52 of the returnedbent lip 5| engages the side wall 4l of the hollow plug head. Aconsiderable engaging force is present due to the resiliency of theskirt 59 of the seal cap and to the fact that inward collapse of suchskirt is substantially prevented by the snug engagement of edges 54 withthe sides of bar 48.

|lhe score lines on the cap of Fig. 6 are slightly different from thoseof Fig. 3 inasmuch as the cross score 55, which is usually the first onepunched, must be set oif to one side of bar 48 However, once cross score58 is broken, tearing along longitudinal score lines 57 can proceed inthe usual manner and the seal cap can then be re-` moved and/ordestroyed.

Having described my invention and what' I claim as new and desire tosecure by Letters Patent is:

1. In structure of the character described, a container wall having anopening therein, an internally-threaded bushing defining said opening, ascrew plug threadedly engaged in said bushing and, in its operativeposition, having its outer face substantially in the plane of the outersurface of the bushing, said plug having the top wall thereof recessedto form a chamber, a toolengaging member extending into said chamberfrom the wall thereof and lying wholly within the chamber, and a sealcap having a top portion closing the mouth of said chamber and adepending skirt portion formed to frictionally engage the side wall ofsaid chamber to prevent removal of the seal cap without destruction ofthe same, said skirt portion having its normal contour interrupted toembrace said tool-engaging member and render the same ineffective whenthe seal cap is in operative position. i

2. In structure of the character described, a container wall having anopening therein, an internally-threaded bushing defining said opening, ascrew plug threadedly engaged in said bushing and, in its operativeposition, having its outer face substantially in the plane of the outer`surface of the bushing, said plug having the top Wall thereof recessedto form a chamber, a toolengaging member extending into said chamberfrom the Wall thereof and lying wholly within the chamber, and a sealcap having a top portion lying within the mouth of said chamber forclosing the same and a depending skirt portion lying along side of andformed to frictionally engage the side wall of said chamber for asubstantial portion of the periphery thereof, said skirt portion havingits normal contour interrupted to embrace said tool-engaging member andrender the same ineffective when the seal cap is in operative position.

3. In structure of the character described, a container wall having anopening therein, an internally-threaded bushing defining said opening, ascrew plug threadedly engaged in said bushing and, in its operativeposition, having its outer face substantially in the plane of the outersurface of the bushing, said plug having the top wall thereof recessedto form a chamber, a toolengaging lug extending into said chamber fromthe wall thereof and lying wholly within the chamber, and a seal caphaving a top portion closing the mouth of said chamber and a dependingskirt portion formed to frictionally engage the side wall of saidchamber to prevent removal of the seal cap without destruction of thesame, said skirt portion being recessed to embrace said toolengaging lugand render the same ineffective when the seal cap is in operativeposition.

4. In structure of the character described, a container wall having anopening therein, an internally-threaded bushing dening said opening, ascrew plug threadedly engaged in said bushing and, in its operativeposition, having its outer face substantially in the plane of the outersurface of the bushing, said plug having the top wall thereof recessedto form a chamber, and a tool-engaging bar extending across saidchamber, lying wholly within the chamber and being secured in placetherein, a seal cap having a top portion closing the mouth of saidchamber and a depending skirt portion formed to frictionally engage theside wall of said chamber to prevent removal of the seal cap withoutdestruction of the same, said skirt portion having opposed portionsthereof removed to embrace said tool-engaging bar whereby said bar isrendered ineffective when the seal cap is in position.

5. A seal cap, for closing the openings in hollow-headed closure plugsand preventing actuation of tool-engaging members extending into suchhollow heads, comprising a disc-like closing portion and a peripheralskirt-like retaining portion therearound, said retaining portionextending substantially laterally with respect to said closing portionand having its normal contour interrupted throughout the height thereoffor reception of the tool-engaging means of a plug, said closing portionbeing formed with weakened sections for rendering the seal cap readilydestructible.

6. A seal cap, for closing the openings in hollow-headed closure plugsand preventing actuation of tool-engaging lugs extending into the hollowof said heads from the sides thereof, comprising a disc-like closingportion, and a peripheral skirt-like retaining portion therearound, saidretaining portion extending substantially laterally with respect to saidclosing portion, said retaining portion and the adjacent part of saidclosing portion being inset to form a continuous channel for thereception of said tool-engaging lug and said closing portion beingformed with weakened sections for rendering the seal cap readilydestructible.

7. A seal cap, for closing the openings in hollow-headed closure plugsand preventing actuation of the tool-engaging bar received within andextending across such hollow heads, comprising a disc-like closingportion and spaced peripheral skirt-like retaining portions extendingsubstantially laterally from the periphery of said closing portion, saidretaining portions having reverselyextending retaining lips formed atthe free ends thereof, and said retaining portions being spaced apart atopposite sides of said closing portion providing slots for reception ofthe tool-engaging bar of the closure plug, said closing portion beingformed with weakened sections for rendering the seal cap readilydestructible.

FLECK W. SAMPLE.

